Arch-center.



D. B. LUTEN:

ARCH CENTER.

APPLIOATION FILED DEC. 23, 1910.

1,005,051 Patented Oct. 3, 1911.

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DANIEL n. LUTEN, or mmanaromsj TNDIANA.

ARCH-CENTER.

Specification of Letters ratent.

Patented Oct. 3, 1911.

Application filed December 23, 1910. Serial No. 598,918.

To all whom it may concern:

Be it known that I, DANIEL B. Lil-TEN, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented a new and useful Improvement in Arch- Centers, of which the following is a specification.

My invention relates to improvements in arch centers and has for its purpose to provide a talsework support for an arch that will have great strength without increased cost for materials or labor.

This invention is illustrated in the accompanying drawings in which the same reference characters designate like parts throughout the views, and in which- Figure 1 is a longitudinal section of an arch supported on 'my improved centers;

Fig. 2 is a detail section of the centers taken transverse to the arch, and Fig. 3 is a detail of one joint of the centers.

The centers comprise supports 1, joists 2, resting upon the supports, riders carried by the oists, and the lagging l coverlng the centers.

1 It has been customary in building centers to out the joist 2 and rider 3 in one piece fr cm a wide board, .with ends framed to meet the next oist over the support 1, on the supposition that the thrust might thereby be transmitted through the joists to assist in carrying the load. But so much settlement results that the uprights are called upon to carry nearly all the load in any event, so much so that the joists frequently crush where they rest on the supports because of insufiicient hearing area. More over after they have been once used such joists can rarely he used again because the next arch will usually have a difi'erent radius.

In my improvement the riders are cut to provide the curved portion only, with enough excess thickness to permit the joist 2 to clear the lagging 4 when lapped past the next joist as at 5. The joists are lapped over supports sufficiently to enable both joists to rest upon the support throughout its entire width as at 6, thus doubling the hearing area of the joists upon the support as compared with the old form in which the joists met, at the middle of thesupport. This lap may be sufficient also to permit the use of stock lengths of lumber for the joists thus eliminating all waste in joist lumber. The'riders .3 rest upon the joists 2 and are carried by them. They need only be second or third grade lumber, to be thrown away after one use. They may even be of one inch boards carried by two inch or four inch joists. They should lap past one another at 7 sufficiently to insure continuity of hearing for the lagging.

The lap 5 of the joists, when securely nailed, prevents any tendency on the part of the joists to warp or twist under excessiveloads.

I claim Arch centers comprising a column, straight joists overlapping and supported upon said column, riders having straight bases and curved upper edges, said riders having their straight bases mounted upon the joists and having sufficient depth to per mit overlapping of the joists on the column without projecting above thecurve of the riders, and the curves of the riders meeting. to form a continuous curve, and lagging mounted on said curved edges of the riders.

In witness whereof, I have hereunto set my hand and seal at Indianapolis, Indiana, this 18th day of December, A. D. one thousand nine hundred and ten.

DANIEL B. LUTEN. a s] Witnesses:

ARTHUR M. H001), THOMAS W. MoMEANs.

copies oi this patent may be obtained for five cents each, by addressing the Commissioner of I'atents, Washington, I). G. 

